Developing a Low-dose CT Lung Cancer Screening Program

Lung cancer is the leading cause of death from cancer in
both men and women, accounting for 27% of all cancer
deaths in the US1 and about 20% globally2. Tobacco
use is the most common risk factor for lung cancer,
with 70% of lung cancer deaths globally occurring in
cigarette smokers. The five-year survival rate of lung
cancer is 17.8%, worse than many other common
cancers including breast (90.5%), prostate (99.6%), and
colon (65.4%).3

Early detection and screening can reduce cancer
mortality. The National Lung Cancer Screening Trial
(NLST) demonstrated a 20% reduction in lung cancer
mortality and cost effectiveness equivalent to other
screening tests with low-dose CT. Based on this trial,
in December 2013, the US Preventative Service Task
Force (USPSTF) recommended annual CT screening
for adults aged 55 to 80 years who have smoked at
least 30 pack-years and are either current smokers or
have quit within the past 15 years. In February 2015,
the Centers for Medicare & Medicaid Services (CMS)
announced a National Coverage Decision for lowdose
CT lung cancer screening and a month later
CMS approved the American College of Radiology
(ACR) Lung Cancer Screening Registry for facilities
to participate in as a requirement of coverage.

In August 2015, GE Healthcare became the first CT
manufacturer with an indication for low-dose CT lung
cancer screening.*

At the University of Michigan Health System,
Ella A. Kazerooni, MD, MS, Chair of the ACR Committee
on Lung Cancer Screening, and Professor of Radiology,
Associate Chair for Clinical Affairs, and Director of
Cardiothoracic Radiology at University of Michigan
Health System, has been instrumental in setting up
the health system’s lung cancer screening program.

“The process of implementing a lung cancer
screening program first involves identifying all the
stakeholders across an institution or health system,”
Dr. Kazerooni says. “It’s easy to think about who
you need in radiology, but it also needs to include
specialists, such as pulmonary medicine physicians
who will likely manage the majority of participants
with positive screening results, oncologists, and
thoracic surgeons. Primary care providers are
critically important to include because screening is
fundamentally a public health tool.”

In setting up the University of Michigan’s Lung Cancer
Screening Program, Dr. Kazerooni and her colleagues
engaged the health system’s population health
program. The most important reason for taking this
approach was to leverage available tools for improving
the health of the local patient population and reaching
out to providers across the health system.

“We needed help identifying who should be screened,”
she explains. “The old fashioned way is through grand
rounds and meeting with physician groups one-onone,
which we do. However, we wanted to leverage
tools such as our electronic health record (EHR) to
make it easy for our primary care physicians to identify
and refer appropriate patients.”

* See gehealthcare.com/lungscreening for a complete list of qualified GE CT scanners and indications for use. Not yet CE marked. For countries that require CE marking, this product cannot
be placed on the market or put into service until made to comply with the Medical Device Directive requirements for CE marking. Not available for sale in all regions.

Along with pulmonary medicine, the population
health group, and the health system’s EHR leadership,
Dr. Kazerooni and her colleagues developed a best practice
alert (also known as a BPA) that will alert physicians
and staff in primary care clinics if their patient should be
considered for CT screening when certain conditions are
met, specifically patient age and smoking history. With
the BPA, clinic staff can order the CT examination, access
a shared decision making aid, and refer the patient to
the tobacco consultation service and/or a high-risk lung
cancer clinic if they would like additional counseling before
considering CT screening. Dr. Kazerooni adds that it is also
important to use a BPA in clinics like cardiology, urology,
and head-and-neck surgery, as these specialists often see
health issues that are smoking-related.

As part of Dr. Kazerooni’s role as Chair of ACR Committee
on Lung Cancer Screening, she has helped develop
several initiatives to bring quality and safe lung cancer
screening practices to physicians groups. One of the first
initiatives was a practice parameter for performance and
interpretation of lung cancer screening CT scans.

“The practice parameter includes the technical
specifications that need to be met to acquire a high-quality
lung cancer CT screening examination,” she explains. “One is
low radiation dose that is adjusted to patient size. Second,
the exam needs to cover the entire lung in a single breath
hold. Third, a slice thickness no greater than 2.5 mm, and
preferably 1 mm, should be used for sufficient resolution
in order to both detect and characterize lung nodules.”
These parameters generally translate to CT systems with
16 detector rows or more, Dr. Kazerooni says. Across the
facilities in the University of Michigan Health System, all
CT scanners are 64 detector rows and, therefore, low-dose
lung cancer screening can be conducted on any system.

Interpreting lung screening studies

As Chair of the ACR Committee on Lung Cancer Screening,
Dr. Kazerooni led the team that developed the Lung Imaging
Reporting and Data System (Lung-RADS™), a standardized
lung cancer screening CT reporting and management
tool to “reduce confusion in lung cancer screening CT
interpretations and facilitate outcome monitoring.”

For reporting purposes, Lung-RADS divides nodules by size
and density (solid, part-solid, and non-solid). Based on the
nodule size and growth pattern over time, the screening
exam is classified on a scale of 0 to 4. Categories 1 or 2 are
considered negative screens and patients are recommended
to continue annual screening. In categories 3 or 4, the
nodules are larger and possibly growing, requiring an interval
test before the next screening exam to better understand
their biologic behavior and likelihood of being lung cancer.
The most aggressive classification is 4B, for which a patient
may next undergo a CT with contrast, PET/CT scan, or tissue

sampling by bronchoscopy or percutaneous biopsy—the
decision should be based on the patient’s individual risk
for cancer and through multi-disciplinary discussion. This is
where collaboration with pulmonary medicine physicians
and thoracic surgeons is critical to tailor the next steps to
what is best for the individual patient, Dr. Kazerooni says.

Although low-dose CT lung cancer screening is designed to
detect cancer, Dr. Kazerooni points out it can also find many
other medical conditions. Lung-RADS makes it very clear
what findings require follow-up for possible lung cancer and
also provides a mechanism for reporting other potentially
significant findings. According to Dr. Kazerooni, these
include an aortic aneurysm; a mediastinal, upper abdominal
or lower neck mass; extensive coronary calcification; and
emphysema. In Lung-RADS, there is a specific designation—
code S—for these findings.

“The two most important other findings that I stress to
our radiologists and others when I talk about lung cancer
screening are emphysema and moderate or severe
calcification,” Dr. Kazerooni says. “With the notion that
lung cancer screening is a public health tool, the three
leading causes of death in the US today all sit in the thorax:
cardiovascular disease, which we can see in coronary arterial
calcification; lung cancer, the number-one cancer-killer in
the US; and COPD and respiratory illness. Emphysema also
increases the patient’s risk of developing lung cancer. We can
make a great impact in public health by finding these diseases
and calling these out for special attention on chest CT scans.”

Keys to success

Dr. Kazerooni has three core recommendations for other
hospitals and health systems seeking to launch a low-dose
CT lung cancer screening program: have a champion, be
flexible, and have the proper infrastructure.

“I firmly believe the champion should be a radiologist, and
that radiologist needs to demonstrate leadership towards
public health and identify a clinical partner champion
either from pulmonary medicine or primary care,” she
says. “This is a partnership between clinical colleagues—
the radiologist who oversees the performance and
interpretation of lung cancer screening CT and the referring
and pulmonary medicine physicians who manage patients
and the positive screens.”

Health systems and hospitals also need to be flexible
in bringing lung cancer screening to different specialties
across clinics and offices. Dr. Kazerooni explains that as
lung cancer screening moves from early adopters to
population health it is critically important to enable
widespread, mainstream screening.

“I don’t think screening can be done only through a
high-risk clinic,” she adds. “If we only accept orders from
a high-risk clinic, then we create a significant bottleneck
to public screening.”

Last, make the case to administration to provide the proper
resources and infrastructure for a comprehensive program.
With the CMS reporting requirement for reimbursement, sites
need to collect information regarding the appropriateness
of screening, radiation dose, the CT interpretation, and
12-month outcomes after a positive screen, including if a
diagnosis of lung cancer was made and any tests performed
to evaluate patients with a positive screen.

“It takes both human and technology resources to collect
the data for the registry and ensure participants are not just
identified, but managed,” Dr. Kazerooni explains.

Dr. Kazerooni also urges radiology practices to use lung cancer
CT screening as an opportunity to encourage abstinence in
current smokers. Many participants who come for screening
are current or former smokers trying to maintain smoking
abstinence. Dr. Kazerooni believes that radiology practices can
help participants who are ready to quit or reinforce that they
should continue to not smoke.

“While we might think that participant consultation is
something that primary care providers are responsible for,
sometimes that readiness for the individual is when they
come for their screening CT. So radiology practices can also
provide information on how to quit smoking and available
resources—it’s just another teachable moment. Don’t forget
that we can play a role in smoking cessation. Smoking is the
largest preventable cause of morbidity and mortality in the
US today and radiologists can make a difference.”